Disposable plastic dish

ABSTRACT

A pair of nestable containers each having bottom and side walls, and a nesting shoulder formed in one of the walls. The shoulder of each container is composed of alternate side and corner segments. The corner segments of one container lie radially beyond the corresponding segments of the other container, while the side segments of the one container lie radially within the side segments of the other container. Therefore, when the two containers are nested together, certain segments of the upper container overlap the corresponding segments of the lower container to prevent jamming.

0 United States Patent 1 1 ,809,236 Davis et al. May 7, 1974 [54] DISPOSABLE PLASTIC DISH 3,l97,058 7/1965 Hale 220/97 D [75] Inventors: Paul Davis, Swampscott; David N. I

Shore, Brookline, b th f M rlrflary Examzr erWill1am T. DlXSOIl, Jr. Asszstant ExamznerJoseph M. Moy Asslgneei Sweetheart Plastics, -a Attorney, Agent, or Firm-Wolf, Greenfield & Sacks Wilmington, Mass.

[22] Filed: July 3, 1972 [57] ABSTRACT [21] Appl. No.: 268,484 A pair of nestable containers each having bottom and I side walls, and a nesting shoulder formed in one of the walls. The shoulder of each container is composed of 7 E -g f g%g alternate side and corner segments. The corner seg- [581 Field 337;;5 22:;2 33 239255732g 23325.3; igrfiiiti fie 2331223221 3252?; side segments of the one container lie radially within [56] References Cited the side segments of the other container. Therefore, when the two containers are nested together, certain I UNITED STATES PATENTS segments of the upper container overlap the corre- 3,672,538 6/1972 Wiedemann 220/97 C sponding segments of the lower container to prevent 3,654,076 4/1972 Hatch 220 97 0 jamming 3,374,923 3/1968 Ettlinger, Jr. et al..... 220/97 D 3,233,812 2/1966 7 Claims, 5 Drawing Figures Kennedy 220/97 C DISPOSABLE PLASTIC msn INTRODUCTION This invention relates to nestable containers and more particularly comprises a new and improved nesting technique for containers, particularly suitable for use with relatively shallow, thin wall, disposable, thermoformed containers such as plates, bowls, etc.

BACKGROUND OF THE INVENTION Thin wall, disposable, plastic containers have a tendency to stick together when arranged in a nested stack, unless some special nesting facility is designed into the containers, which specifically prevents it. In relatively deep drawn thermoformed containers, a well known technique is the provision of undercut stacking rings which support the containers in spaced relationship so that the side walls cannot jam together. In shallower containers such as plates, bowls, etc. where the side walls do not approach the vertical, it has been customary to employ a natural nest wherein the walls of one container lie flush against the corresponding walls of the adjacent containers. Because of the shallow draft of the containers, they are not particularly susceptible to jamming but nevertheless they very often are difficult to separate because they tend to adhere to one another either as a result of static electricity or as the result of an air seal formed between them. In such cases, it is sometimes necessary to fumble with the container edges so as to peel them from one another.

Containers which either jam together or have a tendency to stick to one anotherquite obviously create an annoyance to their users. And in fast food serving establishments, such containers are downright objectionable.

The principal object of the present invention is to provide a nesting facility for shallow containers which does not add appreciably to the stack height of a column of nested containers but which nevertheless prevents the containers from jamming together and otherwise prevents them from adhering to one another.

Another important object of this invention is to provide a nesting facility for shallow, thin wall, disposable, plastic containers which does not increase the amount of material used in the manufacture of the article or otherwise increase the manufacturing costs.

Yet another important object of this invention is to provide a disposable thin wall, plastic, shallow container which will not lie in surface to surface contact with other similar containers with which it is designed to stack. I

To accomplish these and other objects, the nestable containers of this invention are provided with a nesting shoulder having an inner edge which is not a constant distance from the container center. Rather, the nesting shoulder is made upof segments which lie at different distances from the container center. Other containers with which the described container is to nest are similarly provided with nesting shoulders which lie at nonuniform distances from the container centers. The inner edges of certain segments of the nesting shoulder of one container overlap the inner edge of corresponding segments of other containers and prevent jamming or otherwise oppose the containers sticking together.

These and other objects and features of this invention will be better understood and appreciated from the following detailed description of this invention, read in connection with the accompanying drawing in which:

BRIEF FIGURE DESCRIPTION FIG. 1 is a plan view of a dish constructed in accordance with this invention;

FIG. 2 is a line drawing showing the outline in plan of a nesting shoulder of a second container designed to stack with the container of FIG. I;

FIG. 3 is a line drawing highlighting the cross sectional differences of the containers shown in FIGS. 1 and 2;

FIG. 4 is a fragmentary cross sectional view showing two containers nested together; and

FIG. 5 is a line drawing similar to FIG. 2 and suggesting the manner in which the nesting shoulders of the containers cooperate.

DETAILED DESCRIPTION The containers shown in the drawing are thin wall, disposable, plastic, thermoformed dishes which have a shallow central portion 10 composed of a bottom wall I 12 and a very short side wall 14, and a rim 16 which is generally flared upwardly and outwardly from the inner edge 18 that is coincident with the top edge of the side wall 14. Rim 16 forms a smaller angle with the horizontal than does the side wall. As illustrated in FIGS. 3 and 4, the outer portion 20 of rim 16 has a downturned skirt 22 which joins the main portion of the rim at radius 24. The configuration of the outer portion 20 of the rim may take many different forms, and details for no part of this invention.

The configuration of the rim 16 at its inner edge 18 is critical to the nesting ability of the container with other similar containers. Path A which describes the periphery of the container may be and preferably is the same for all of the containers of this invention which are designed to nest with one another. Similarly, the curvature of the rim 16 is the same for all the various containers which are designed to stack with one another. There are, however, differences in the edge configuration 18 defined by path B in FIG. 1 and path C in FIG. 2. The differences in those paths result in the slightly different cross sectional configurations for the side walls 14 of the two containers and the radial extent of the rims 16. This is particularly apparent in FIGS. 3 and 4.

To fully describe the distinctions between the two containers, the following description is presented with certain specific dimensions, but these dimensions are not intended to limit the invention in any way. Rather, they are presented to illustrate the differences between the configurations of the containers represented in FIGS. 1 and 2, which enable them to nest together without sticking or otherwise adhering to one another.

The rim 16 of the dish shown in FIG. 1 is composed of alternate comer and side segments 30 and 32 whose outer edge is described by path A and whose inner edge is described by path B. Path B which is coincident with edge 18 is made up of corner radii X and side radii Y that merge smoothly with one another. Path C in FIG. 2 on the other hand is made up of corner radii X and side radii Y so that there is a slightly perceptible difference in the configuration of the shoulder defined by edge 18 in the dishes shown in FIGS. 1 and 2. The different radii result in the dish of FIG. 2 having a more nearly square shape than that of the dish of FIG. 1, which is more nearly round. Consequently, when the two dishes are placed in stacked relationship one on the other, paths B and C intersect one another in the manner suggested in FIG. 5. Each of the two paths undulate with respect to the container center, and they are out of phase with one another when the two are circumferentially aligned with respect to their overall shape (path A). Because of this difference in the shapes of the rims of the two dishes, (see difference illustrated by overlay of the profiles in FIG. 3), the rims form nesting shoulders adjacent their inner edges, bounded by edge 18, which shoulderssupport'the side walls of the next upper dish in the stack so that the two are prevented from lying in face to back contacting relationship over their entire surfaces. I

In FIG. 4 the manner in which the containers nest together at the interfering portions of the rim is shown. When the container of FIG. 1 rests on top of that of FIG. 2, the edge 18 of the container of FIG. 2 at the side portions 32' engages the wall 14 of the upper container so as to separate the two containers a distance approximately equal to one half the vertical extent of the side wall l4. Thus, at four points about the rim (the four sides), the upper container is supported on the rim of the lower container. If in turn a container as shown in FIG. 2 rests on top of a container like that shown in FIG. 1, the lower container will support the upper container at the corner segments 30 of the rim while no support will be offered the upper container at the side segments. It will be appreciated that in production and packaging alternate forms of containers are selected to comprise the stack so as to avoid identical containers from lying immediately adjacent one another. No continuous line contact is made about the nested containers which could form a sealed chamber between the bottoms 12 that would interfere the containers.

The configuration of this invention provides interference between adjacent containers either at the corner segments or side segments of the rim but the differences between the containers are so slight when viewed separately that one would not readily recognize that the several containers in a stack are not all identical. Therefore, the nesting facilities in no way detract from the apparent uniformity of the containers when placed on a table.

EXAMPLE Two dishes manufactured and tested in accordance with the present invention have the following dimensions, which provided a most satisfactory nesting relationship. The average thickness of the stock is approximately 0.0l4-0.018 inch. The width of both dishes measured across path A is 8.468 inches. Radius X is 2.625 inches and radius X is 2.4687 inches. Radius Y is 5.5625 inches, and radius Y' is 6.875 inches. These dimensions provide an overlap at the inner edges at the points of maximum interference of approximately 0.030 inch, which exceeds stock thickness and is sufficient to prevent jamming of the dishes or container adherence to one another when they are stacked together.

Having described this invention in detail, those skilled in the art will appreciate that numerous modifications may be made of. this invention without departwith easy separation of 5 claims and their equivalents.

edge of the side wall, said rimsextending outwardly at a smaller angle to the horizontal than the side walls, and the inner edges of the rims forming nesting shoulders, said inner edge of the rim of one container being defined by alternate radii of different sizes, and the inner edge of the rim of the other container being defined by radii different from the radii of the one container, one of the radii of said other container being larger than the corresponding radii of the one container and the other of the radii of said other container being smaller than the corresponding radii of the one container. 2. A pair of nestable containers as described in claim further characterized by the outer edges of the rims of the two containers being identical. 3. A pair of nestable containers comprising first and second containers each having a'bottom wall and side wall and a nesting shoulder having an inner edge formed in one of said walls, said shoulder being composed of alternate side and corner segments, the distance of the corner segments measured from the container center of one container to the inner edge being larger than the corresponding distance in the other container, and the distance of the side segments measured from the container center of the one container to the inner edge being smaller than the corresponding distance in the other container, whereby when the two containers are nested together, the inner portions of certain of the shoulder segments overlap the corresponding shoulder segments of the other container, and prevent jamming of the containers together. 4. A pair of nestable containers comprising first'and second containers each having a bottom wall and side wall and a nesting shoulder having an inner edge formed in one of said walls, said inner edges undulating with respect to the container center and with the undulations being out of phase with one another. 5. A pair of nestable containers as described in claim 4 further characterized by the two containers having an outer edge which is identical in plan, and said undulations being out of phase when the outer edges are circumferentially aligned. 6. A pair of nestable containers as described 5 further characterized by said containers outer edges being other than round.

in claim 7. A pair of nestable containers as described in claim 6 further characterized by said container outer edges being generally rectangular with rounded corners, and one of said rounded corners and one side of said outer edge forming one undulation cycle. 

1. A pair of nestable containers comprising two disposable, thin wall, plastic containers each having a bottom and side wall and a flared rim extending outwardly from and being integral with the top edge of the side wall, said rims extending outwardly at a smaller angle to the horizontal than the side walls, and the inner edges of the rims forming nesting shoulders, said inner edge of the rim of one container being defined by alternate radii of different sizes, and the inner edge of the rim of the othEr container being defined by radii different from the radii of the one container, one of the radii of said other container being larger than the corresponding radii of the one container and the other of the radii of said other container being smaller than the corresponding radii of the one container.
 2. A pair of nestable containers as described in claim 1 further characterized by the outer edges of the rims of the two containers being identical.
 3. A pair of nestable containers comprising first and second containers each having a bottom wall and side wall and a nesting shoulder having an inner edge formed in one of said walls, said shoulder being composed of alternate side and corner segments, the distance of the corner segments measured from the container center of one container to the inner edge being larger than the corresponding distance in the other container, and the distance of the side segments measured from the container center of the one container to the inner edge being smaller than the corresponding distance in the other container, whereby when the two containers are nested together, the inner portions of certain of the shoulder segments overlap the corresponding shoulder segments of the other container, and prevent jamming of the containers together.
 4. A pair of nestable containers comprising first and second containers each having a bottom wall and side wall and a nesting shoulder having an inner edge formed in one of said walls, said inner edges undulating with respect to the container center and with the undulations being out of phase with one another.
 5. A pair of nestable containers as described in claim 4 further characterized by the two containers having an outer edge which is identical in plan, and said undulations being out of phase when the outer edges are circumferentially aligned.
 6. A pair of nestable containers as described in claim 5 further characterized by said containers outer edges being other than round.
 7. A pair of nestable containers as described in claim 6 further characterized by said container outer edges being generally rectangular with rounded corners, and one of said rounded corners and one side of said outer edge forming one undulation cycle. 